1. Soil & Mulch. It’s best to use a professional potting mix rather than actual soil—never use soil right out of the garden. The lighter professional potting mixes give excellent root stability and allow for lots of air around growing roots. Promix is a good variety, but there are other mixes that contain perlite for drainage and some peat. Once planted, mulch the soil on top of the pots to conserve moisture, about an inch will do. If soil becomes bone dry it stresses plants out—especially on a very hot, sunny day. Stick your finger through the mulch to see how wet the soil is to know when to water.
2. Use the biggest pots available. From a practical standpoint, the bigger the better when it comes to containers. Large pots dry out more slowly and keep roots cooler, so less stress on the plants. Bigger pots make watering less of an issue: No matter how cute a series of small terra cotta pots look on a windowsill, unless you are prepared to stand there with a hose on the hottest days, it’s often a death sentence for plants. (Unless they are succulents and cactus.) Make sure all pots have holes for water drainage, by the way.
3. Position your pots close to a hose, or have a big watering can. It sounds ridiculously obvious, but more plants have died because the owner was too busy to run and get a hose coiled up way at the end of the garden. With a conveniently placed hose, watering can be done in a matter of minutes, on your way to somewhere else. Mine often call to me as I’m walking to the car, and I can quickly squirt some water at them. It’s quick and easy. Your success increases by making it as easy as possible for yourself to do the Do Things. Get a large size watering can if you don’t have a hose nearby, not too big that your arms are falling off, but not too small either, so you don’t have to make so many trips.
4. Choose drought hardy plants. As far as flowers, geraniums (technically Pelargoniums) are the old standby, they can take a lot of heat and drought. There are some great new hybrids out now, with interesting leaf variegation and shapes. Some are snobby about geraniums, thinking them too common, but I love them. (I always think of the lovely effect of a single pot of geraniums on a window sill in Paris.) Casading geraniums are particularly drought tolerant. Other drought hardy annuals are verbena, nasturtium, portulaca, cosmos, scaveola, cleome, and butterly-attracting lantana. Petunias can withstand a bit of drought, but if they are let dry out too many times, they will suffer. You can grow perennials, like sedum, in pots as well, but the flowering season is shorter. You can mix edibles and flowers in a container, but make sure they all have the same level of drought tolerance.
5. Fertilize and rejuvenate. Every two weeks, give your containers an addition of organic fertilizer, like fish or seaweed fertilizer that you mix with water. Rejuvenate means cutting plants back part way through the season when they start to look leggy, like petunias, or violas. Also, many plants need deadheading: taking off the old flowers to clean the plant, and also to stop it from making seeds. You want plant energy to go to flowers, not making seeds. New growth will be spurred and your container will have a new lease on life. If anything looks bedraggled, you can pull it out and pop in a small pot of something new and fresh. Fiesta Gardens has plant material right through the season, so check there for refills.